1. Field of the Invention
This invention relates generally to teaching devices, and more particularly to teaching devices that can be used for conducting and observing, e.g., science experiments involving fluids and/or other materials.
2. Background
Teachers, especially those who teach courses in the physical sciences, commonly use teaching aids or devices for conducting experiments in their classrooms. Such devices help the teachers carry out the experiments under controlled conditions to demonstrate, e.g., known laws or effects to their students or test new hypotheses. It is therefore important that such devices enable groups of students to view the experiments all at the same time, thereby facilitating the teachers' instruction of science in the classroom setting.
In addition, because students often perform science experiments individually or in small groups, it is important that such teaching aids or devices are convenient and easy-to-use. This is especially the case in high school and the lower grades, where there are often students with a range of skill levels. Further, because such devices must often be reused over and over by successive classroom groups, it is important that such devices are durable and easy-to-maintain.
Teachers have used various types of teaching aids or devices for conducting science experiments in the past. For example, teachers have used devices such as test tubes, flasks, and beakers for performing experiments involving fluids and other materials. However, these devices have drawbacks because they are normally relatively small in size and therefore are not easily viewed by groups of students. Further, these devices are typically fragile and easily broken, thereby posing a potential hazard to students who are called upon to perform experiments themselves. In addition, students often find it difficult to transfer fluids and other materials into and out of these devices when performing experiments. As a result, spillage often occurs, thereby affecting the results of experiments and directly exposing the students to the fluids and other materials.
In U.S. Pat. No. 5,242,307 ("the '307 patent") issued Sep. 7, 1993, to Reinbold, a teaching apparatus or teaching tank is described. In accordance with that disclosure, a teaching tank has two (2) substantially planar walls, i.e., front and rear walls, at least one of which is transparent. A plurality of bolts and spacers, or molded fasteners, are used for holding the front and rear walls in a parallel opposed spaced relationship to form a tank volume, which is defined by the planar dimensions of the front and rear walls and the tank cavity width determined by the spacers. The tank side walls and bottom are formed using flexible and deformable tubing, such as PVC tubing, which is sealingly compressed by the front and rear walls when they are assembled. The deformable tubing defines in combination with the planar walls at least one working cavity having a working cavity volume. The volume and/or volumes are variable and a function of the placement of and the dimensions of the tubing and the planar walls.
However, the teaching apparatus described in the '307 patent also has some drawbacks. For example, that teaching apparatus has a number of parts including the front and real walls, the bolts and the spacers, and the deformable tubing. As a result, teachers and students may easily lose one or more of these parts, thereby rendering the teaching apparatus virtually useless. Even if all of the parts are available, teachers and students may find the teaching apparatus of the '307 patent difficult to assemble and take apart, thereby making the teaching apparatus difficult to set-up, clean, and maintain.
It would therefore be desirable to have a teaching device that can be used more easily for conducting and observing, e.g., science experiments involving fluids and/or other materials. Such a device would be suitable for performing both classroom demonstrations and individual student experiments. It would also be desirable to have a device for conducting science experiments that is inexpensive, has a small number of parts, and is easy-to-use and maintain.